A paper guiding mechanism including a slidingly movable paper guide member is known in general. Such a paper guiding mechanism is disclosed in Japanese Patent Laying-Open No. 7-285681, for example.
In the aforementioned Japanese Patent Laying-Open No. 7-285681, there is disclosed a paper feed cassette (a paper guiding mechanism) including a paper placing plate (a base member) including a placing surface for placing papers thereon and a lock groove (a base-side lock portion) provided to extend in a prescribed direction along the placing surface and a paper guide member mounted to be slidingly movable in the prescribed direction with respect to the paper placing plate. A paper cassette includes a guide portion (a paper aligning portion) formed to extend in an upper direction with respect to the placing surface of the paper placing plate for coming into contact with edge portions of the papers placed on the placing surface of the paper placing plate. Further, the paper cassette includes a pressing lever having a lock projection (a guide-side lock portion) locked to the lock groove of the paper placing plate. An elastic portion held by two notches extending in the upper direction with respect to the placing surface of the paper placing portion is formed on the guide portion. The guide portion and the pressing lever portion are configured to be connected with each other through the elastic portion. This paper cassette is configured to upwardly lift the lock projection on the lower portion of the pressing lever for canceling a locked state of the lock projection with respect to the lock groove by inclining the pressing lever toward the guide portion when placing large-sized papers. Further, the paper cassette is configured to be adjustable to a size suiting the large-sized papers through the guide portion slidingly moved to the side of the pressing lever in an unlocked state where the aforementioned locked state is canceled.